Blocking your own trailer
 

I know there was a previous thread on it, but no consensus seemed to be reached and that topic was getting way.. off topic.

It seems to be this is a hugely viable strategy, and I don't want to end up wasting a week designing for it, for it to then become illegal.

Is the general consensus if you find a way to stay within the size limitations, you can cover up your own trailer?

=/

Re: Blocking your own trailer
 

I'd be shocked if the game designers don't eventually say that physically covering your goal is illegal. Even if there were a hole in the rules that may allow it, I think they would call you for a violation of the spirit of the rules.

Re: Blocking your own trailer
 

Now, I wouldn't be surprised if some rule to that effect is introduced today or tomorrow, but what in the rules as they stand now makes you think that the "spirit of the rules" bars you from covering your goal?

Re: Blocking your own trailer
 

Although the rules might allow it...would we really want games with all the trailers covered and robots just driving around without being able to score anything?

I'm guessing they'll clarify in the near future though.

Re: Blocking your own trailer
 

Rules state you cannot go out of the dimensions of your robot, therefore not allowing you to cover up your robot.

Re: Blocking your own trailer
 

Yes, that is true but some teams are thinking about retracting the trailer inside their robot and then covering the top or covering it somehow or just retracting it in so it is harder to see

Re: Blocking your own trailer
 

Actually,

<R16>
Once the MATCH has started, the ROBOT may assume a PLAYING CONFIGURATION that is different from the STARTING CONFIGURATION. The ROBOT must be designed such that the PLAYING CONFIGURATION of the ROBOT shall not exceed the dimensions specified in Rule <R11>.

This would imply that if your total robot stayed within the maximum size, then you could have some extension (that might be a cover).

(note - not saying it is legal or in the spirit, just listing what the rule says)

Re: Blocking your own trailer
 

These are questions that should not be lumped together. I'll start a list of questions that might be asked in the Q&A. Feel free to modify them and add new ones to the list.

1. If a robot is built with, say, a 24x24 footprint, is it allowed to expand beyond that to the max 28x38 footprint dimensions?

2. If #1 is permissible, can the 28x38 max footprint of the robot overlap with that of a trailer, self-towed or otherwise?

3. If #2 is permissible, are teams allowed to erect a cover/diverter above the portion of a self-towed trailer which overlaps the 28x38 max footprint?

4. If #2 is permissible, are teams allowed to employ descoring mechanisms to extract game pieces from trailers? [My "gut feeling" says this will not be allowed.]

5. If #2 is permissible, excluding the obvious exception of the trailer hitch point, may a robot contact any part of a trailer other than its bumpers?

6. Can the 38" dimension be the "wide" dimension of the robot? [I'm almost positive this will be allowed.]

Until the opening of the Q&A on Wednesday or the release of a Team Update, further speculation is pointless, and a consensus opinion is meaningless.

Re: Blocking your own trailer
 

hmm ... retract the trailer?

Can you think of a way to do that without violating <R18>D. and R<18>E. ? Look carefully at Fig. 8-6 and consider the restrictions that <R18> places on how the robot is permitted to constrain the trailer's motion.

[edit]see also: Nate's analysis of the fixed trailer hitch location requirement <R18>B.[/edit]

If you do think of a way, it would be smart to post a question for the GDC using the official Q&A on the FIRST forum, to make sure your idea doesn't violate a rule. It would be a shame to base your team's robot design on an assumption that turns out to be incorrect.

Re: Blocking your own trailer
 

#1=Yes.
Nos. 2-4 are, in my opinion, currently legal. I would not be surprised if some of them are not by tomorrow, though.

#5=Yes.
#6 has always been legal, and there is nothing in the rules that leads me to believe anything has changed this year.

Re: Blocking your own trailer
 

I agree with Richard. R18E will seriously restrict any trailer enclosure strategy.


If you guys think that the GDC didn't think of the idea of covering the trailer prevent scoring then you don't know them very well. I think they wrote the rules to make it almost impossible to do so they will not issue any new rule preventing it. If a team comes up with a viable way of doing it within the rules I think the whole GDC will congratulate them.

Re: Blocking your own trailer
 

in response to the robot width being the 38" direction - I believe this is totally legal but it does state in the rules that the trailer will be attached to the SHORT side of the robot. so, if the robot design had the wide sides in the front and back, then the trailer would be sliding along beside it on the left or right.

Re: Blocking your own trailer
 

I don't think there's anything that says that in rule <R18>, the rule regarding the trailer hitch. It just has to be somewhere on the outside of the robot. Is there somewhere else I'm not looking?

Re: Blocking your own trailer
 

I did not see that in the manual... see below

<R18>

Re: Blocking your own trailer
 

please quote this rule?

Re: Blocking your own trailer
 

I didnt see this in the rules. You may have made a mistake while reading
<R18>BThe Trailer Hitch must be rigidly attached to a fixed location on the ROBOT, with the long dimension of the Trailer Hitch horizontal and the opening of the C-channel facing away from the ROBOT. The horizontal center line of the Trailer Hitch must be 2-13/16 inches above the floor.

Re: Blocking your own trailer
 

My team while brainstorming thought of a blower such as a low amp leaf blower that could b angled to blow moon rocks away from the trailer. we decided against one because it would use like all of our battery second because its prolly gunna b outlawed

Re: Blocking your own trailer
 

Could you quote this rule? Thanks.

Re: Blocking your own trailer
 

I don't think it will be outlawed, but it probably would consume a lot of battery power.

I don't think this is a rule at all. If it is i know i missed it.

Re: Blocking your own trailer
 

Okay - I am trying to find the actual location where we (both my wife and I) read this - but I cannot find it!!!!!

I am so sorry if this is not the case. I was not intentionally trying to mess everyone up. We actually were thinking of rotating our robot so the front was wide but after reading this "rule" decided that was not an option.

we have a printed version of the rules that we printed out on the first day - could this have changed on the web site since? I would think that any change would have to be sent out as a notification to all teams.

Re: Blocking your own trailer
 

Well here is the complete section about trailer location on the robot:

<R18>
To attach the TRAILER to the ROBOT, TEAMS must use a Trailer Hitch constructed from materials provided in the 2009 Kit Of Parts. Details on the construction of the Trailer Hitch are provided in Drawing “GE-09040.”
A.
The Trailer Hitch is composed of the “Trailer Spacer” (Part 2 in the referenced drawing) and the “Trailer Mount Bar” (Part 3 in the referenced drawing). The Trailer Spacer is a 7-inch length of square steel tubing provided in the Kit Of Parts. The Trailer Mount Bar is a 7-inch length of robot chassis material (C-channel) to be cut from the provided KOP chassis material.
B.
The Trailer Hitch must be rigidly attached to a fixed location on the ROBOT, with the long dimension of the Trailer Hitch horizontal and the opening of the C-channel facing away from the ROBOT. The horizontal center line of the Trailer Hitch must be 2-13/16 inches above the floor.
C.
The Trailer Hitch must be positioned so that the TRAILER may be locked in place with a standard 1/4– inch diameter hitch pin (McMaster-Carr part number 98416A009). During a competition MATCH, this hitch pin will be provided with the TRAILER as part of the ARENA equipment. See Figure 8-5.
D.
The Trailer Hitch must be located on an outer edge of the ROBOT structure such that it may easily connect with the tongue of the TRAILER (attached to the TRAILER).
E.
The Trailer Hitch must be placed such that, as the TRAILER swings from side to side, the first contact between the TRAILER and ROBOT is BUMPER-to-BUMPER and not TRAILER-tongue-to-BUMPER (to prevent placing excessive stress upon, and possibly damaging, the TRAILER tongue). See Figure 8-6.
F.
The color of the TRAILER (red or blue) will be used to indicate the ALLIANCE of the ROBOT.

No where does it state that you can't place it on the long side of the robot, so it seams it's ok!

Re: Blocking your own trailer
 

#4 is definitely illegal, I'm looking for the rule now, but I remember reading that balls can not be taken from the trailers after being scored.

Re: Blocking your own trailer
 

so if we keep it at the limit of the box then we can extend an arm backwards to decrease the chance of a ball making it into the trailer?

Re: Blocking your own trailer
 

Seeing that teams are brainstorming an air defense, how effective do you think that would be?

My team thinks its a rather great idea and so do I but the mathematics seems to worry me... I may be thinking far to ahead but its better early than never...

Re: Blocking your own trailer
 

Two words: Bill's Blog:)

Re: Blocking your own trailer
 

if anyone can help me, i really need to knwo trailer dimensions. my team is trying to make one to recruit payload specialists.

Re: Blocking your own trailer
 

I think you may be mistaking it with the rule where if a trailer tips over, all balls in it still score. I don't think there is, as of yet, any rule that says what you are saying.

EDIT: Just noticed this-http://frcdirector.blogspot.com - which states that "the Game Design Committee’s intention" is that de-scoring, goaltending, and under-robot fans are not allowed. So I wouldn't make plans to use any of them, but it is still my opinion that they are technically legal. Until today's Team Update, that us...

Re: Blocking your own trailer
 

What if the fans were placed near the top? Would that violate any rules?

Re: Blocking your own trailer
 

Well what you could do is create a robot that is really small, then when you create the cover your robot will not go outside the limits since your robot is already tiny to begin with. Also one rule states that you need all balls able to be taken out of your trailer at the end of the match without powering your robot back up so if you were to make something, you would need to make it retractable at the end of the match.

Re: Blocking your own trailer
 

im going to quote bills blog on this one:

"Good Morning Teams,

I want to clarify the Game Design Committee’s intention on a few matters to save you time and resources:
1) De-scoring is not permitted (ie. You may not remove game pieces from a trailer)
2) Goal tending is not permitted (ie. You may not block access to a trailer)
3) Don’t spend time attempting to develop a vacuum car system like Jim Hall’s sucker Chaparral car. Even a slight suction over the base of the robot will damage the field surface and you don’t want to do that (See the 2009 FIRST Robotics Competition Manual section 7 rules G-29 & G-30)"

which in essence says NO blocking the trailer, and that it will probably be specified directly in a team update.

Re: Blocking your own trailer
 

what about a robot, full size with that fans tucked in against the top? of course i also mean under the height limit?

Re: Blocking your own trailer
 

If you haven't seen this from Bill's Blog today:

If you cannot block access to a trailer, I presume you cannot block access to any trailer, your own included.

So in short, no, you cannot block your own trailer.

Trailer weight?
 

Does anybody know what the weight of the trailer should be?

Re: Blocking your own trailer
 

Blowing air isnt blocking as far as we have seen, people will still be able to score and it isnt technically physical blocking... being one to have seen Bill's Blog...

Re: Blocking your own trailer
 

I'd have to say blowing air towards the trailers with the intent of deflecting balls is a means of blocking, no?

If you ask this on the Q&A, I'm willing to bet that the GDC responds that this is against the intent of the rules, and is not legal.

Re: Blocking your own trailer
 

I guess i will ask...

Re: Blocking your own trailer
 

I would consider blowing air a means of goal tending, and since goal tending is illegal blowing air would be too.

EDIT: the quote didn't show, just look at Smurfgirl's post to see what i am talking about

Re: Blocking your own trailer
 

Iwanttoduck,

From <R18>,

Re: Blocking your own trailer
 

With the official team update the descoring option is canceled for good.
Just read what the team update says:

And if that's not plain and simple enough:

Disappointing, isn't it ? :(

Re: Blocking your own trailer
 

Sorry if this is a redundant qestion but CAN we take balls out of the trailors while up-right?

Re: Blocking your own trailer
 

While you CAN, the rules certainly do not want you to :)

Re: Blocking your own trailer
 

I would think not because any way to do that would involve deploying some arm into the basket. The violates the rule of blocking because even though the arm won't be there the whole time you are still blocking the hole for the time being. Also, you can't break the perimeter of your trailer with your robot.

Re: Blocking your own trailer
 

you cant, if you start with a dimension of 20x20, you cannot go outside for the 20x20. i havent seen this rule personally but my advisor told me this when we were discussing design. and you cannot retract the trailer into the robot buecause the trailer has to be able to piviot freely

Re: Blocking your own trailer
 

It is painfully obvious that you haven't seen that rule, because it doesn't exist. In the future you may want to adopt the habit of quoting the specific rule (you can cut from a PDF document and paste it here in Cheif Delphi)

The first relevant rule is <R11>
At the start of, and during, the MATCH the ROBOT shall fit within the dimensions listed below: (28 x 38 x 60 inches)

Then we have <R16>
Once the MATCH has started, the ROBOT may assume a PLAYING CONFIGURATION that is different from the STARTING CONFIGURATION. The ROBOT must be designed such that the PLAYING CONFIGURATION of the ROBOT shall not exceed the dimensions specified in Rule <R11>.

Re: Blocking your own trailer
 

If you made a 28"x28" robot then you could have 10" to cover the trailer without having to worry about the trailer touching your robot or the rule about fixing your trailer hitch in one position. This could work if you had no bumper on the back then there would be no backside barrier for the limit in terms of the rule that you cant extend past the bumper zone. If there is no bumper zone in the rear then you can extend out over the trailer.
Think about that

Re: Blocking your own trailer
 

Considering that ur trailer can not go within the frame of the robot and that arms can go outside the frame....this seems near impossible any way, but I don't think there are any rules specifically forbidding it.

Re: Blocking your own trailer
 

I think you misunderstand the meaning of BUMPER ZONE. It refers to the entire region of the arena from 1" to 7" above the floor. Wherever your robot is, a slice of it exists within the BUMPER ZONE.

The BUMPER PERIMITER is closer to what you're talking about. However, it completely surrounds a robot at the BUMPER ZONE height, and no part of the robot may extend beyond it (with exceptions for the trailer hitch and the bumpers themselves, of course).

Re: Blocking your own trailer
 

i think there is a rule that the trailer has to be conected to the outer most point of the robot:confused: :confused:

Re: Blocking your own trailer
 

All it says is that:
<R18>D:
There are other parts of this rule too, but there isn't any rule saying it has to be on the outer most point as far as I am aware.

Re: Blocking your own trailer
 

To quote Inspector Clouseau [bad French accent] "Not anymore." [/bad French accent]

You need to keep up with the rule changes. See Team Update 1 and Robot Rules revision B. It now reads

Re: Blocking your own trailer
 

When I read that it doesn't say it has to be on the outer most point, just as long as it is easy to attach. (outer most point being a point on the bumper perimeter as described in the update)

Re: Blocking your own trailer
 

It doesn't have to be on the outermost point, but it does have to be on the BUMPER PERIMETER which is defined by the robot's outermost points:

Re: Blocking your own trailer
 

That was what I was originally intending to say by quoting <R18>, sorry if I didn't get that clear the first time.

Re: Blocking your own trailer
 

So, does that mean that for example, if a robot was shaped like this (letters in place to form the shape; look at the lines):
III_______
II/RRRRRRR\
I/RRRRRRRR\
|__|SSS|__| (I know, bad representation, but you get the idea)

Then would the bumper perimeter be shaped like this?
III_______
II/RRRRRRR\
I/RRRRRRRR\
|_________|


Definition:

BUMPER PERIMETER – the polygon defined by the outer-most set of exterior vertices on the ROBOT
(without the BUMPERS or Trailer Hitch attached) that are within the BUMPER ZONE. To determine
the BUMPER PERIMETER, wrap a piece of string around the ROBOT at the level of the BUMPER
ZONE - the string describes this polygon. The BUMPER PERIMETER may extend up to, but cannot
exceed, the maximum ROBOT volume constraints defined in Rule <R11>.

According to the definition of the bumper perimeter, if you draw a string around your robot then that defines your bumper perimeter, and that is how it would look if you took a string around and held it taut, correct?

-Zach

Re: Blocking your own trailer
 

Yes. They have stated that the intention of the rule is something along the lines of that "if your robot were to collide with a wall, the bumpers would collide before any other part of your robot would".

Ahh, here we go.

Re: Blocking your own trailer
 

But, if there were to be a cut out in the robot, then the bumper would still contact first, wouldn't it? Not that it matters for our reasons though. We had looked into making the trailer basically part of our robot, but none of us were looking at Revision B of section 8 (the complete manual file hasn't been updated with Rev. B yet). <R18> D clarified that this can't be done and the trailer must be free instead of snug in your robot.

Re: Blocking your own trailer
 

You are correct. Due to that update, the trailer must be attached to the bumper perimeter, which means no cutouts to brace it. (And no other braces either.)